Double-throw safety-switch



L. KELLNER. DOUBLE THROW SAFETY SWITCH. APPLICATION FILED SEPT 10, 1918. RENEWED FEB. 26, 1920.

Patented Oct. 5, 1920.

4 SHEETS-SHEET l- ATTORNEY L. KELLNER.

DOUBLE THROW SAFETY SWITCH. APPLICATION FILED SEPT. 10. 1918. RENEWED FEB. 26, 1920.

1,354,764, Patentd 00$. 5,1920.

4 SHEETSSHEET 2.

V y {I /III III IIIIIIII I 7/ 'NVENTQR /1 /1 A 7 2.5 a ATTORNEYJ L. KELLNER.

DOUBLE THROW SAFETY SWITCH. APPLICATION FILED SEPT 10. I918. RENEWED FEB. 26, 1920.

4 3HEETSSHEET 3.

I? /Z i 4 40] 2? ATTORNEYS L. KELLNER. DOUBLE THROW SAFETY SWITCH APPLICATION FILED SEPT. 10, I918. RENEWED FEB. 26, 1920.

1,354,764. Patented Oct. 5, 1920.,

UNITED STATES PATENT OFFICE.

DOUBLE-THROW SAFETY-SWITCH.

Specification of Letters Patent.

Patented Oct. 5, 1920.

Application filed September 10, 1918, Serial No. 253,441. Renewed February 26, 1920. Serial No. 361,423.

To a7l whom itm'ag concern:

Be it known that I, LOUIS KELLNER, a citizen of the United States, and resident of the borough of Brooklyn, county of Kings, city and State of New York. have invented certain new and useful Improvements in Double-Throw Safety-Switches, of which the following is a specification, (Case F.)

One of the main objects of this invention is to provide a safety snap switch adapted for use on two circuits, the switch having three positions, one for each of the circuits and an intermediate or neutral position, the switch mechanism being so designed that the contact brushes may be quickly snapped into any one of the three positions.

In carrying out the invention I have illustrated in the drawings forming a part hereof. a switch mechanism operable through a hand lever and whereby the brush-carrying plate or block may be moved fromeither its inner or outer position to its intermediate neutral position, or from the neutral position to either the inner or outer position, with a snap or quick action. In the manipulation of the operating lever the brushes will remain stationary until the throw of the lever is complete, whereupon the brushcarrying plate will be released from one position and quickly snapped into the next position.

Another object of the invention is to provide in a switch of this type a safety closure means whereby the fuse plugs will be covered and inaccessible at all times except I when the brush block or plate is in its neutral position and, of course, tree from both sets of terminals. Obviously the purpose of this is to prevent any attempt to remove or replace fuse plugs when the circuit is complete through either set of contacts.

Another object of the invention is to provide a double-throw switch of the type de scribed, wherein a single motor spring will be employed for snapping the brush-carrying block into any one of its three posi-- vide in a switch 9], the type described a single motor spring for moving the brushcarrying block, said spring being placed under tension by the movement of the switch operating lever, the direction of movement of the lever determining the tension on the spring and the direction of movement of the brush-carrying block through said spring.

There are other important objects and advantages of the invention which will be hereinafter described, or which will be obvious to those skilled in the art to which this invention pertains.

In the drawings, Figure 1 is a transverse sectional view of the inclosing casing, the switch mechanism being shown in end elevation, parts thereof being broken away and shown in sectional view to more clearly illustrate certain features of construction;

Fig. 2 a longitudinal sectional view on the line 11-11 of Fig. 1, the inclosing casing being omitted;

Fig. 3 a detail sectional view on line III-J11 of Fig. 5, of the brush block releasing means when the brush block is in neutral position, as illustrated in Fig. 2;

Fig. 4 a similar view of the releasing means with the brush block in its upper position as shown in Fig. 11;

Fig. 5 a artial transverse sectional view on the line V of Fig. 2;

Fig. 6 a detail side elevation of the latch releasing means;

Fig. 7 a sectional view thereof on the line VII-VII of Fig. 6;

Fig. 8 a detail sectional view of the latch disk;

Fig. 9 a detail sectional view of the latch disk on the line IXIX of Fig. 8;

Fig. 10 a detail elevation of the face of the latch disk;

Fig. 11 a detail sectional view of the switch showing the brush block in its upper position;

Fig. 12 a similar view showing the brush block in its lower position;

Fig. 13 a detail elevation of one of. the gears and racks for shifting the brush block;

Fig. 14 a horizontal sectional view on the line XIV XIV of Fig. 12;

Fig. 15 a longitudinal sectional view of the inclosing casing of the switch showing the switch in elevation and illustrating the safety cover;

Fig. 16 a sectional view similar to Fig. 3, of the brush block releasing means, show ing the position of the parts when the brush block is about to be moved from its upper position to neutral position;

Fig. 17 a similar view with the parts in a position about to release the brush block from its neutral to its lower position:

F ig. .18 a similar view when the brush block is in its lower position; and

Fig. 19 a detail sectional view of the cover mechanism.

Referring to the various parts by numerals, 1 designates the base of the switch to which is secured the rigid standards 2, said standards being connected together by a bottom plate 3. It is obvious, however, that they need not be so connected but may be independent standards mounted on the block. These standards are at opposite sides of the base, and extending between them near their upper ends is a transverse rock shaft 4. At each end of the said shaft near the inner faces of the standards is rigidly secured a pinion 5, said pinions being adapted to engage the rack 6 formed on the inner faces of slotted arms 7, said arms at their lower ends carrying the brush block 8. It is manifest that by rotating the rock shaft 4 in the proper direction the brush block, with its slotted arms, will be raised or lowered. As shown in Fig. 13, the pinions 5 may be mutilated, and provided with only suflicient teeth to secure the proper movement of the brush block. To the lower side of the brush block are secured two sets of brushes 9 and 10, the lower set 9 being adapted to be carried down into engagement with the lower contact plates '11, said plates'being connected to circuit wires 12 and to fuse plug connections 13. The upper set of brushes 10 is adapted to be moved into engagement with upper contact plates 14 which are connected to circuit wires 15 and fuse plug connections 16. The brushes are insulated from the brush block by means of insulation plates 17 and properly insulated bolts 18. The space between the upper and lower sets of contact plates is sufficient to permit the brush block and the brushes to be placed in a neutral position between them, in which position the brushes will be out of contact with both sets of contact plates. Fuse plug connections 13 and 16 are connected in any suitable manner with the fuse plug clips 19; fuse plugs 20, and circuit wires. 21, all of said devices being preferably mounted on the base 1 as indicated in Fig. 15, and in a convenient position to be inclosed within a. suitable protecting box.

Rigidly mountedon the rock shaft to turn therewith, and closely adjoining one of the pinions 5, is a latch disk 22, said disk being preferably made up of three plates 23, 24 and 25 securely pinned together, side by side, as shown clearly in Figs. 1 and 5. The innermost disk 25 is formed with an annular cam slot 26 having a somewhat flattened portion 27, as shown clearly in Fig. 10. Mounted in a recess formed in the central plate 24 is a spring-pressed trip pin 28, said pin projecting through the plate 25 at a point radially beyond the flattened portion 27 of the cam slot, the end of said pin being rounded andprojecting slightly above the outer face of the plate 25. Rigidly secured to the latch disk at a point diametrically opposite the trip pin, and near the circumference of the disk, is a transversely extending bar or actuating pin 29, said pin being adapted to engage and hold one or the other end of the power spring, as will be more fully hereinafter described. The latch disk, at a point diametrically opposite the actuating pin 29, is formed with an inwardly extending recess 30, the sides of said recess being formed by radially arranged yieldable jaws 31. Said jaws are pressed to their outermost position by springs 32 arranged in recesses formed in the central plate 24 of the latch disk. The outward or substantially radial movement of the jaws is limited by pins 33 which fit in grooves formed in the said jaws, as clearly shown in Fig. 8. The outer ends of the jaws conform to the curvature of the circumference of the latch disk. The adjoining portions of the plates 23 and 24 are beveled inwardly to the bottom of the recesses 30, as indicated clearly in Figs. 8 and 10, for a purpose which will be hereinafter set forth. The latch disk is formed with a reduced concentric surface 34, said reduced part constituting approximately one-half of the circumference of the disk. At the ends of this reduced part of the disk are formed two inwardly extending locking notches 35, the remaining portion of the latch disk being somewhat enlarged in diameter. Secured to one of the standards 2, directly below the latch disk, is a socket 36 in which is mounted a latch bolt 37 whose upper end is adapted to fit in the locking recesses 30 and the. locking notches 35. A spring 38 normally presses the latch bolt toward the latch disk. The latch bolt is provided on its inner face with an upwardly extending beveled lug 39, said lug normally lying in the path of trip devices, as will be hereinafter described.

Loosely mounted on the rock shaft 4 is a rotatable sleeve 40 to which is rigidly attached an upwardly extending operating lever 41. The lever is provided with a laterally extending setting pin 42 which projects toward the latch disk and lies parallel with the actuating pin 29 carried by said disk. Surrounding the sleeve 40 is a power spring 43 whose ends are substantially parallel and extend in the same direction radially with respect to the rock shaft. One end 44 of said spring lies close to and on one side of the pins 29 and 42, and the other end 45 lies close to and on the opposite side of the pins 29 and 42, so that said pins lie between the two outwardly extending ends of the power spring, the pin carried by the operating lever being closer to the rock shaft than the actuating pin carried by the latch disk. It is manifest that by moving the operating lever in either direction the setting pin will move one or the other end of the spring, thereby causing the other end to increase its pressure against the actuating pin. By this arrangement a single spring is used to rotate the latch disk and the connected rock shaft and pinions in either direction, the movement of the op erating lever serving to tension the spring in the desired direction. The tension thus placed upon the operating spring will tend to move the latch disk in the direction in which the operating lever has been moved in order to set the power spring under tension. The movement of the lever merely sets the power spring, said spring operating the switch mechanism when the latch disk is released. In this way a very rapidly operating quick-make-andbreak switch is provided wherein the actual making or breaking of the circuit will not take place until the operating lever has completed its movement.

Secured rigidly to the end of the rotatable sleeve 40 adjacent the latch disk is a trip disk 46, so that said disk will follow the movements of the operating lever. Pivotally mounted on that face of the trip disk adjoining the latch disk is a trip yoke 47, said yoke being formed with the two releasing cams 48 and 49 at the ends of its arms, the pivot of said yoke being midway the ends thereof; and the arms of said yoke are of sufficient length to permit the releasing cams to be projected beyond the periphery of the trip disk, as the trip yoke is oscillated on its pivot by means which will be hereinafter described. The trip disk, at a point diametrically opposite the pivot of the trip yoke, is formed with parallel, substantially radial flanges 50 between which is mounted a radially movable trip dog 51, said dog being provided at its inner end with a pin 52 which fits within and is guided by the cam groove 26 of the latch plate. The cam groove is so disposed that when the pin 52 is in the circular portion thereof the trip dog will be projected beyond the periphery of the trip disk, said trip dog being retracted or drawn inwardly by the flattened portion of the cam groove so that its end pivot thereof, is formed with two notches 53 and 54 in which is adapted to snap a spring-pressed locking dog The ends of the arms of the trip yoke are adapted to be engaged by the trip pin 28 of the latch disk as the trip disk is rotated through the operating lever. The trip pin 28 is designed to throw one or the other arm of the trip yoke outwardly into the path of the beveled lug 39 of the latch bolt 37, the movement of the trip yoke depending upon the direction of movement of the operating handle. The inner faces of the arms of the trip yoke are slightly beveled, as shown clearly in Fig. 6, so that when the latch disk is rapidly rotated under the impulse of the power spring, the said pin 28 will be pressed inwardly out of the path of the said arms and will not prevent or interfere with the rotation of the latch disk and the said pin will not be injured by violent contact with the trip yoke arms.

lVith the parts in lower circuit-closing position, as shown in Figs. 12 and 18, the brush block may be shifted to neutral posit-ion to break the connection between the contacts 11 by swinging the handle 41 toward the right, as vlewed in the drawings, to its vertical central position shown in Fig. 15. This movement of the handle rotates trip disk 46 in the direction indicated by the arrow in Fig. 18, the initial movement of said disk causing the end 49 of trip yoke 47 to ride over lug 39 on the latch bolt and rock the yoke to retract the cam end 49 and project the cam end 48. As the disk 46 continues to rotate the pin 52 on trip dog 51 will engage in the circular portion of the cam slot 26 in latch disk 24, thus projecting the trip dog 51 in the path of the beveled lug 39 on the latch bolt 37. As the trip disk completes its movement the latch bolt will be forced downwardly by the trip dog 51 out of the notch marked L in Fig, 18, whereupon the motor spring, which has been placed under tension by the movement of pin 42 on the handle 41 relatively to pin 29 on latch disk 24, will rotate the latch disk with a rapid snap action to the position shown in Fig. 3 and the latch bolt will snap into the notch 30 in the latch disk. This rotation of the latch disk will bring the straight part of the cam slot to a position to again retract the trip dog 51, as shown in Fig. 3, and move the brush block to the position shown in Figs. 1 and 2. If, after the operation just described, it is desired to return the mechan sm to the lower Circuit-closing position,

the operating handle is swung back to the left as indicated by the arrow V marked Lower in Fig. 15. In moving the lever toward the leftthe trip disk, the yoke and the trip dog will move as indicated in Fig. 17. .Vhen the arm 49 of the trip yoke engages the trip pin 28 it will be swung on its pivot to cause the arm 49 to extend beyond the periphery of the trip disk and into the path of the beveled lug 39 on the latch bolt; the other arm of the trip yoke will be swung into engagement with'one of the flanges 50, said flange forming a rigid stop to prevent any further swinging movement of the trip yoke. As the operating lever is forced downwardly to complete its operating stroke the cam end 49 of the trip yoke will force downwardly the latch bolt and free it from the latch disk. The movement of the operating lever has swung downwardly the end 45 of the power spring thereby causing the end 44 to bear with increased tension against the actuating pin 29. As soon, therefore, as the latch bolt has been forced downwardly out of the latch recess 30 the power spring will rotate the latch disk through the actuating pin 29, thereby rotating the shaft 4 and the pinions 5 in the direction to throw downwardly the rack 6, arms 7 and the brush block carried thereby. The latch disk will make a quarter revolution, or until the two ends of the power spring again engage the setting pin 42 carried by the operating lever. At this point in the rotation of the latch disk the latch bolt 37 will be projected by its s ring into one of the locking notches 35. s viewed in Fig. 17 the latch bolt will snap into the locking notch marked L. The parts then will be in the position shown in Figs. 12 and 18.

If, after the switch has been operated as above described to break the connection between the lower contacts 11, and the parts are in the neutral position shown in Figs. 1, 2, 3 and 15, it should be desired to close the circuit through the upper contacts 14, the handle 41 is swung to the right as indicated by the arrow marked Upper in Fig. 15.

This movement of the handle will rotate the trip disk 46 to'cause the cam end 48 of the trip yoke, which was projected to the position shown in Fig. 3 during the movement from' lower position to neutral, 'to release the latch bolt from notch 30 in the latch disk, whereupon the motor spring will rotate the latch disk to the position shown in F igs. 4 and 11 and the latch bolt will snap in the notch marked U in the latch disk as shown in Fig. 4. This movement of the latch disk willcause the pinions 5 to shift the brush block to the position shown in Fig.11, thus closing the circuit between the upper contacts 14.

In order to move the switch block from its upper po ition to its neutr l p s t on the operating lever is moved from its lower right-hand position to its upper midway neutral position. This movement of the operating lever will cause the rotation of the trip disk and the trip devices in the direction indicated by the arrow in Fig. 16. This movement of the trip disk will first cause the end 48 of the trip yoke to ride over the beveled lug 39 on the latch bolt and rock the trip yoke to the position shown in Fig. 16 with the end 49 thereof projected, and will then bring the pin 52 into the circular portion of the slot 26, thereby projecting the trip dog beyond the periphery of the trip disk and into the path of the lug 39 of the latch bolt. The circular portion of the slot will hold the trip dog rigidly extended, and as the operating lever completes its upward movement the latch bolt will be forced downwardly and freed from the latch disk, thereby permitting the power spring to rotate the latch disk and the pinions in the direction to lift the brush-carrying block to its midway or neutral position. When the actuating pin is again parallel with the setting pin and the two ends of the power spring are in engagement with both of said pins the latch bolt will snap into the locking recess 30 as indicated in Fig. 3, in which position it will be held between the yieldable jaws 31. If the latch bolt does not accurately strike within the recess 30, but engages either one of the yieldable jaws, the said jaw will yield and permit the latch bolt to engage the inwardly beveled walls of registering recesses formed in the plates 23 and 25 of the latch disk and be thereby guided to its proper central position whereupon'the inwardly pressed yieldable jaw will spring outwardly and engage the latch bolt.

When the switch is operated to shift the brush block from upper position to neutral position as just described, the parts will assume the positions shown in Figs. 2 and 3, except that the trip yoke 47 will be rocked in the opposite direction with the end 49 thereof projected in position to release the latch bolt upon a subsequent movement from neutral to lower position. If, with the parts in this position, the handle 41 is operated to return the mechanism to upper position, rotation of the trip disk will cause arm 48 of the trip yoke to engage trip pin 28 and the yoke will be rocked to project arm 48 into position to trip the latch bolt.

It is unnece$ary to provide yieldable jaws on opposite sides of the locking notches 35, for the reason that the enlarged part of the latch disk projects into the path of the latch bolt and insures the bolt entering the looking notches.

It is ,manifest that the trip devices .will not be actuated until the operating lever has completed its movement. It is also manife'st that if the operating lever be not moved sufficiently to operate the trip devices the said lever will be returned by the power spring to the point from which it was moved, and there will be no operation of the switch devices. It is also manifest that in order to complete the movement of the operating lever a final thrust must be given to it in order to release the latch bolt from the latch disk. The strength of this thrust will be dependent upon the strength of the spring 38.

The switch mechanism is preferably inclosed within a protecting box 56, the fuse plugs being directly below a hinged cover 57. One of the arms '7 of the brush-carrying block is extended downwardly as at 58 in Fig. 1, and said extension carries an outwardly extending pin 59, said p1n be1ng adapted to reciprocate in a slot 60 1n the adjacent standard Q. Mounted to slide longitudinally in the box 56 is a locking plate 61, said plate being guided in suitable ways arranged along its upper and lower edges. The pin 59 extends into a T-shaped slot 62, the shorter member of said slot being vertical as shown in ig. 15 and the longer member thereof extending to the left from said shorter member. In the neutral position of the operating lever, as indicated in Fig. 15, the pin 59 is at the junction of the two members of the T-slots so that in said position of the operating lever the locking plate may be moved toward the ri ht longitudinally of the inclosing box. ecured to the hinged cover 57 is a depending arm 63, at the lower end of which is an outwardly extending pin 64 which engages in a vertical slot 65 in the locking plate. It IS manifest that when the operating lever is in its neutral position the cover 57 may be raised, the pin 64 sliding the locking plate 61 and the pin 59 entering the long horizontal member of the T-slot 62. When, however, the operating lever is in either its upper or lower position the pin 59 will be at one or the other end of the short member of the T-slot and out of line with the longer member thereof. It is manifest that in this position of the parts the cover 57 cannot be raised as it will be locked by the pin 64 and the arm 63. It is clear, therefore, that the fuse plugs cannot be reached without first placing the brush block in its neutral position. It is also manifest that the protecting cover 57 must be closed to inclose the fuse plugs before the operating lever can moved from its neutral position.

What I claim is:

1. In an electric switch, the combination of two oppositely disposed pairs of stationary contacts, a reciprocable contact-bridging means located between said pairs of contacts, an operating handle rotatable in opposite directions, a motor spring, a rack held to said contact-bridging means, a pinion meshing with said rack, and means actuated by said handle adapted to store power in said spring for rotating said pinion to shift the contact-bridging means with a snap action from an intermediate off position to on positions bridging either of said pairs of contacts and from either on position to off position.

2. In an electric switch, the combination a of two oppositely disposed pairs of stationeither contact-bridging position to its intermediate oif position.

3. In an electric switch, the combination of two oppositely disposed pairs of stationary contacts, a reciprocable contact-bridging means adapted to bridge either pair of contacts and having an intermediate off position between said pairs of contacts, a rotatable operating handle, a rotatable locking plate, a spring-pressed latch adapted to lock said plate in its several positions, a

motor spring, means whereby rotation of said handle will place said motor spring under tension and then release the same by releasing the locking plate, and means operable by the motor spring and locking plate when the locking plate is released to snap the contact-bridging means from its intermediate 01f position into engagement with either pair of contacts or from a position bridging either pair of contacts to its intermediate off position.

4. In an electric switch, the combination of two pairs of stationary contacts, contactbridging means having an off position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the motor spring for storing power in the spring to rotate said element in the direction of movement of the handle, means controlled by the handle for releasing said latch after a predetermined movement. of the handle from either on position to off position, and means controlled by said handle for releasing said latch after a pre' determined movement of the handle from off position to either on position.

5. In an electric switch, the combination of two pairs of stationary contacts, contac bridging means having an off position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses and a cam groove, a latch adapted to engage in either of said recesses. a coiled motor spring, connections between said handle and element and the motor spring for storing power in the spring to rotate said element in the direction of movement of the handle, means rotatable by the handle and engag ing in said cam slot in the rotatable element to move radially of said element when the handle is rotated for releasing said latch upon movement of the handle from either on position to its off position, and means controlled by said handle for releasing said latch upon movement of the handle from off position to either on position.

6. In an electric switch, the combination of two pairs of stationary contacts, contactbridging means having an oil position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses and a cam groove, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the motor spring for storing power in the spring to rotate said element in the direction of movement of the handle, means rotatable by the handle and engaging in said cam slot in the rotatable element to move radially of said element when the handle is rotated for releasing said latch upon movement of the handle from either on position to its off position, a latch releasing device rotatable with said handle and having a rocking movement relatively thereto to shift said device to positions to release-said latch upon movement of the handle from off position to either on position and means for automatically rocking said device to position the same to release the latch in either direction of movement of the handle from off position.

7. In an electric switch, the combination of two pairs of stationary contacts, contactbridging means having an off position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses and a cam groove, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the motor spring for storing power in the spring to rotate said element in the direction of movement of the handle, means rotatable by the handle and engaging in said cam slot in the rotatable element to move radially of said element when the handle is rotated for releasing said l'atch upon movement of the handle from either on position to its off position, a latch releasing device rotatable with the handle and pivoted intermediate its ends to rock relatively to the handle to shift either end of said device into position to release the latch upon movement of the handle from oil position to either on position, one end of said device being adapted to engage the latch to shift the opposite end thereof to latch releasing position upon movement of the handle from either on position to its olf position, and means for resetting said device upon movement of the handle from off position to the on position from which the handle was last shifted.

'8. In an electric switch, the combination of two pairs of stationary contacts, contactbridging means reciprocable between said pairs of contacts having an off position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses, a rack held to said contact-bridging means, a pin ion meshing with said rack and operable by said element, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the motor spring for storing power in the spring to rotate said element in the direction of movement of the handle, means controlled by the handle for releasing said latch upon movement of the handle from either on position to 01f position, and means controlled by the handle for releasing said latch upon movement of the handle from off position to either on position.

9. In an electric switch, the combination of two pairs of stationary contacts, contactbridging means reciprocable between said pairs of contacts having an intermediate off position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses and a cam groove, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the spring for storing power in the spring to rotate said element in the direction of movement of the handle, a pinion rotatable with said element, a rack held to said bridging means and meshing with said pinion, means rotatable by the handle and engaging in said cam slot in the rotatable element to move radially of said element into position to release the latch u on movement of the handle from either on position to its olf position, and means controlled by said handle for releasing the latch upon movement of the handle from off position to either on position.

10. In van electric switch, the combination of two pairs of stationary contacts, contact-bridging means reciprocable between said pairs of contacts having. an intermediate ofl' position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses and a cam groove, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the spring for storing power in the spring to rotate said element in the direction of movement of the handle, a pinion rotatable with said element, a rack held to said bridging means and meshing with said pinion, means rotatable by the handle and engaging in said cam slot in the rotatable element to move radially of said element into position to release the latch upon movement of the handle from either on position to its off position, a latch-releasing device rotatable with said handle and having a rocking movement relatively thereto to shift said device to positions to release the latch upon movement of the handle from oif position to either on position, and means for automatically rocking said device to position the same to release the latch in either direction of movement of the handle from 0E positron.

11. In an electric switch, the combination of two pairs of stationary contacts, contactbridging means reciprocable between said pairs of contacts having an intermediate off position and two on positions, an operating handle rotatable in opposite directions, a rotatable element having three spaced recesses and a cam groove, a latch adapted to engage in either of said recesses, a coiled motor spring, connections between said handle and element and the spring for storing power in the spring to rotate said element in the direction of movement of the handle, a pinion rotatable with said element, a rack held to said bridging means and meshing with said pinion, means rotatable by the handle and engaging in said cam slot in the rotatable element to move radially of said element into position to release the latch upon movement of the handle from either on position to its off position, a latch-releasing device rotatable with the handle and pivoted intermediate its ends to rock relatively thereto to shift either end of said device into position to release the latch upon movement of the handle from off position to either on position, one end of said device being adapted to engage the latch to shift the opposite end thereof to latch-releasing position upon movement of the handle from either on position to its off position, and means for resetting said device upon movement of the handle from off position to the on position from which the handle was last shifted.

12. In an electric switch, the combination of two oppositely disposed pairs of stationary contacts, contact-bridging means, a support, a shaft journaled in said support, a

pinion fixed on said shaft, a rack held to said bridging means and meshing with said pinion, a disk rotatable with said shaft having three spaced recesses therein, a springpressed latch adapted to engage in either of said recesses, an operating handle rotatable about said shaft, a motor spring coiled about said shaft having projecting ends, arms carried by said disk and handle extending between the projecting ends of said spring, and means controlled by said handle for disengaging said latch bolt from either of said recesses in the disk.

13. In an electric switch, the combination of movable circuit-closing means having two on positions and an intermediate off position, an operating handle rotatable in opposite directions, a motor spring, a rack connected with said circuit-closing means, a pinion meshing with said rack, and means actuated by said handle adapted to store power in said spring for rotating said pinion to shift the circuit-closing means with a snap action from its intermediate off position to either of its on positions and from either on position to its off position.

14. In a double-throw switch, the combination of two pairs of stationary contacts, an operating handle rotatable in opposite directions, a motor spring, means for placing said spring under tension when the bandle is rotated in either direction, contactbridging means, an element rotatable, by said spring operatively connected to reciprocate the bridging means from an intermediate olf position to positions bridging either of said pair of contacts and from either contact-bridging position to its intermediate off position, a latch for locking said element against rotation, and means controlled by the handle for releasing said latch after a power-storing movement of the handle.

15. In a multiple-throw electric switch, the combination of terminal-bridging means having an off position and a plurality of on positions, a rotatable element operatively connected to shift the bridging means, an operating handle, a latch adapted to antomatically engage and lock said element against rotation in its several positions, a motor spring, means controlled by said handle for storing power in said motor spring to rotate said element, and means rotatable relatively to said element and latch by the handle for releasing said latch after a powerstorin movement of the handle.

16. ii an electric switch, the combination of circuit-closing means having an off position and two on positions, an operating handle, a rotatable element, a latch adapted to automatically engage and lock said element in either of three positions, a mo tor spring, connections between said handle and element and themotor spring for storing power in the spring to rotate said element in either direction, means controlled by the handle for releasing said latch after a predetermined movement of the handle from elther on position to off position,

and independent means controlled by the handle for releasing said latch after a predetermined movement of the handle from 10 off position to either on" position.

In testimony whereof I hereunto afl'ix my signature.

LOUIS KELLNER. 

